Consult service helps reduce genetic test misorders

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An intervention designed to reduce genetic test misorders among medical practitioners is having a positive impact at Stanford University, according to a report in this issue. A test review and consulting service consisting of a genetic counselor, a molecular pathologist, and a medical geneticist reviewed 629 orders for high-cost tests over the 2015 calendar year. Of these, 13% (n = 82) were categorized as misorders. Reasons for misorders included clerical errors, redundant testing, alternative approaches, controversial orders, and uncategorized orders. Most misorders fell into the "controversial" category, which the group defined as test orders with no underlying scientific evidence of test utility for the suspected condition. After consultation, more than half of orders were modified or canceled. Over the course of the year, the number of consultations increased and the number of misorders decreased. Since the ordering physicians initiated consultations, there was a learning curve over which practitioners learned of the existence of the new service. However, the research team reported that as health-care providers became familiar with the program, its impact became apparent. They concluded that the very existence of the genetic test review carried an educational message about the wise use of health-care resources that could ultimately reduce the incidence of misorders. –Karyn Hede, News Editor

Genomic sequencing reveals very high rate of thalassemia carriers among Dai people in China

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The first study to use next-generation sequencing (NGS) for thalassemia screening among ethnic Dai people in China reveals that one in two people are carriers, a rate much higher than previously reported. A collaborative team based in Yunnan Province conducted the premarital screening study among the Dai, an ethnic minority. The Dai people are closely related to the Lao and Thai people, of Southeast Asia. People are classified as Dai in China if at least one of their parents belongs to the Dai ethnic group and they typically speak a Thai language. Among these closely related ethnic groups, the incidence of thalassemia, which can cause debilitating severe anemia due to mutated or missing globin genes, is known to be high. The research team identified 12 distinct types of α-thalassemia mutations and 11 types of β-thalassemia mutations, including some rare mutations first detected in this study. In total, nearly half of those tested (471/951) were thalassemia mutation carriers. The findings also revealed similarities among the mutations and genotypes that suggest that the Dai and Thai nationalities may share a common ancestry and genetic kinship with the Kinh in Vietnam. Importantly, the research team reported that the NGS approach significantly reduced false-negative results and obviated the need for repeated testing or clinical referral. The high carrier rate reinforced the importance of providing effective premarital screening in regions of the world where α-thalassemia carriers or β-thalassemia minor are prevalent, thus preventing severe thalassemia and reducing pediatric mortality. –Karyn Hede, News Editor